Check if value exist in datatable

Question

i have sql command and I save values into datatable.

con.Open();
cmd0.CommandText = "Select ......";
DataTable dtbl = new DataTable();
dtbl.Load(cmd0.ExecuteReader());

And i have value String Name. I need to know, if the value in String Name is in the datatable dtbl...It is possible?

Maybe you could use a SqlDataReader to get the information, another stack question explains how to here: http://stackoverflow.com/questions/4018114/read-data-from-sqldatareader — Michael B, Nov 12 '13 at 15:26

Thilina H · Accepted Answer · 2013-11-12T15:47:30.123

Since there's only a single value returned, you could do this:

string value = (string)command.ExecuteScalar();

Anyway the DataTable has a collection .Rows of DataRow elements.Each DataRow corresponds to a record row in your database.

If you want to access a single value, do something like this:

   foreach(DataRow row in dtbl.Rows)
     { 
         if(row["ColumnName"].ToString()=="Name")
         {
         }      
     }

mehmet mecek · Answer 2 · 2013-11-12T15:48:05.383

1

Yes it is possible, you can use DataTable.Compute method like as follows.

string valueToSearch = "lorem";
string columnName = "Name";
int count =
    (int) dtbl.Compute(string.Format("count({0})", columnName),
        string.Format("{0} like '{1}'", columnName, valueToSearch));

edited Nov 12 '13 at 15:48

answered Nov 12 '13 at 15:41

mehmet mecek

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Now i have this error: Syntax Error: Before the LIKE operator is missing operand. – Kate Nov 13 '13 at 09:05
You can use `=` instead of `like`. where clause should be written here just like in a SQL sentence (`select count(Name) from dtbl where Name like 'yourName'`). Additionally the answer above, that loops in dtbl.Rows and checks the equality, is costful, dtbl.Compute method already does what you needed. – mehmet mecek Nov 13 '13 at 09:57

Check if value exist in datatable

2 Answers2